In an environment absent from human influence, there has been a balance between the earth and atmospheric greenhouse gases. Since the industrial age, human based activity has resulted in what is known as the greenhouse effect. Contributors to the greenhouse effect are:                Methane        Carbon oxides                    carbon monoxide CO and carbon dioxide CO2                         Nitrous oxides (NOx)                    unreactive gaseous nitrogen, N2             reactive NO3−, NO2−, NO, N2O and NOx                         Sulphur oxides (SOx)                    mainly SO2 and SO3                         Volatile Organic Compounds (VOCs)        Particulate Matter (PM)        Carbon-Halogen Compounds        Sulfur halogen compoundsCarbon dioxides are the most common greenhouse gas. “Methane is twenty-one times as potent as carbon dioxide according to the US Environmental Protection Agency” (Segelken, Roger. “Cornell biologists aim to grow ‘bugs’ responsible for greenhouse gas, methane, in NSF-funded microbial observatory.” Cornell News 8 Feb. 2002). “N2O is a greenhouse gas that is two hundred times more effective per molecule than is CO2 in absorbing infrared radiation. “N2O is a potent greenhouse gas with an estimated 5% contribution to global warming, owing to its long residence time in the atmosphere (150 years) and its relatively high infrared absorbance (>200 times that of carbon dioxide)” (Apel, William A., Turick, Charles E. “The use of denitrifying bacteria for the removal of nitrogen oxides from combustion gases.” Fuel, Vol. 72, Issue 12, pg. 1715-1718, 1993). In addition, N2O in the stratosphere reacts with excited oxygen in the presence of ultraviolet radiation to produce NO, which catalyzes the destruction of stratospheric ozone (O3). Given that the atmosphere is already 78% N2, N2 emissions to the atmosphere via denitrification have no significant atmospheric effects, although these losses may influence ecosystem nitrogen pools. Atmospheric N2 has a turn over time of thousands of years” (“Chapter 8. Terrestrial Nutrient Cycling.” Principles of Terrestrial Ecosystem Ecology Chapin III, F. Stuart, Matson, Pamela, Mooney, Harold A. 1st ed. 2002 Corr. 2nd printing, 2004, XIV, 436 p. 199 illus.). Ultraviolet rays enter the earth's atmosphere and are normally deflected back through the ozone layer. The NOx emissions react in the ozone layer trapping ultraviolet radiation leading to global warming known as the greenhouse effect.        